“She fought valiantly against the apartheid state and sacrificed her life for the freedom of the country,” the spokesman said in a statement. “She kept the memory of her imprisoned husband Nelson Mandela alive during his years on Robben Island and helped give the struggle for justice in South Africa one its most recognizable faces.”

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Winnie Madikizela-Mandela, an anti-apartheid campaigner and wife of former South African President Nelson Mandela, is seen in Johannesburg in December 2017.

Madikizela-Mandela was known as a tireless activist who spent decades standing up against racial segregation and discrimination imposed by the South African government from 1948 to 1994.

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South African anti-apartheid activist and politician Nelson Mandela is seen with wife Winnie Madikizela-Mandela in the early '90s.

After Mandela was sentenced to life behind bars for treason in 1964, Madikizela-Mandela became known for carrying on his activism. Her work, which earned her the nickname “Mother of the Nation,” led to her own years-long detention, arrest, torture, and banishment by white authorities.

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Madikizela-Mandela, seen in early 2017, was memorialized on Monday as a leader and a survivor of “the most brutal period of state terror in apartheid South Africa.”

In 1993, she separated from Nelson Mandela, who was elected president of South Africa the following year. She was fired from his Cabinet following allegations of corruption not long after. They divorced in 1996.

In later years, Madikizela-Mandela both defended and apologized for her actions. “I am not sorry. I will never be sorry,” she told the London Evening Standard in 2010. “I would do everything I did again if I had to. Everything.”

The Nelson Mandela Foundation mourned her death Monday in a statement that recognized her as a leader and a survivor of “the most brutal period of state terror in apartheid South Africa.”

“All South Africans are indebted to Mama Winnie, whether they acknowledge it or not,” Professor Njabulo Ndebele, the foundation’s chairman, said. “From the witness of her life, we knew we could stand tall; we knew also we could falter and stumble. Either condition was an affirmation of life. Her cry was our cry, and in 2018 we can say we did triumph.”